I think you are missing my point. The USA itself is not one thing, and the laws are not one thing. Specifically, by design and in fact, people's rights to do a wide variety of things, were and are still, different. The language you are insisting on, is misinformation.

https://www.aclu.org/know-your-rights/discrimination-on-the-...

The post you replied to said:

> Up until about 1971 (possibly later, but that's the date of Loving vs Virginia), the US had formal, legal discrimination against black people.

And you seem to be arguing that this is “misinformation”. The best I can make of your objection is that, prior to 1967, the US did not outlaw miscegenation and that it was merely 16 states that did so and that these laws were legal in the US. This is IMO unhelpful nitpicking — the OP’s point had nothing to do with which books the laws were written in and also did not depend on all states being affected.

(The connection between miscegenation and college admissions is rather more distant than, say, the discrimination outlawed not too much earlier by Brown v Board of Education, but even that is a bit of a nitpick.)